Snatch-block



(No Model.)

T. R. FBRRALL.

SNATGH BLOCK.

Patented June 3, 1884.

. apl/ ATENT F ICEO THOMAS R. FERRALL, OF BOSTON, MASSACHUSETTS.

SNATCH-BLOCK.

SPECIFICATION forming part of Letters Patent No. 299,531, dated June 3, 1884.

Application filed April 28, 1884. (No model.)

To all whom it may concern:

Be it known that I, THOMAS E. FERRALL, a citizen of the-United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Snatch-Blocks; and I do hereby declare that the same are fully described in the following specification and illustrated in the accompanying drawings.

This invention relates to improvements in snatch-blocks, and it is carried out as follows, reference being had to the accompanying drawings, where- Figure 1 represents a front elevation of the improved block. Fig. 2 represents a vertical 1 section 011 the line A B shown in Fig. 1, and

Fig. 3 represents a-vertical section on the line 0 D shown in Fig. 2.

Similar letters refer to similar parts wherever they occur on the difierent parts of the drawings.

In the drawings, a represents the front or short side of the block, and 1) represents the long or rear side of it, as usual.

a is a metal bowstrap clasping over the in and out side of the front side piece, a, and having a bent loop, a, in its upper end, as shown. In practice I prefer to extend the inner end of the bow-strap a to the lower end of the block, as shown in Fig. 2, and to make the outer end of said bow-strap only long enough to enable it to receive the pulley spindle or bolt 0. b is a similar metal bow-strap clasping over the in and out side of the rear side piece, I), and having a bent loop, b, in its upper end, as shown in Fig. 2, and I prefer to extend the inside of said strap 1) to the lower end of the block, and to make its outside only long enough to enable it to receive the pulley-spindle c, as shown in Fig. 2.

d is the sheave or pulley, located loosely on the spindle bolt or rivet c, that passes through it, the side pieces, a b, and their respective metal bow-straps a b, as shown in Fig. 2.

The lower ends of the side pieces, a b, are

united by means of rivets c e, passing through them and the wooden end piece, f, the latter holding the side pieces apart the proper distance, according to the width of the sheave that is used. To strengthen the block in its lower end, as well as to prevent the side pieces,

of the shrinkage of the Wooden end piece, f,

as may take place in dry weather. The improved metal-lined end piece, ff, is also advantageous for many other reasons, among which may be mentioned that by its use the wood part f is prevented from splitting and falling to pieces, which it wouldotherwise be liable to do on account of the rivet-holes bored through it to unite it with the sides of the block. The said end piece may be made of all metal; but it would increase the weight of the block materially, particularly in a snatchblock, where such end piece has to be very wide, so as to obtain proper bearing-surfaces for holding it onto the side pieces.

To the loop b of the rear bow-strap, b, is hinged the head 9, made of metal, and having in one piece with it or journaled to it the hinge-pin 9, that rests loosely in the loop b, as shown in Fig. 2.

Midway on the head 9, and through a perforation at or near such part, is inserted the shank h of the hook h, such shank h being riveted in its lower end, or provided with a suitable head or enlargement, as is usual, so as to permit said shank to turn freely in the head without getting detached therefrom.

On the forward end of the head 9, and in one piece with it, is cast the locking projection g, with a lip, 9 on the side of it, as shown in Fig. 2, the object of which will be hereinafter described.

To the loop a of the front bow-strap, a, is hinged the metal link i by means of hingepin 1), resting loosely in the said loop a. Such hinge-pin t" is preferably cast in one piece with the link i, but may be journaled to it in any suitable manner without departing from the spirit of my invention.

Through the upper end of thelink i is made a suitable perforation, 1?, through which the locking projcctiong and its lip y" are inserted after the rope has been laid over the sheave within the upper end of the block. For the purpose of retaining the block in such a closed position while in use, I provide the link i with a frictional locking device constructed as follows: By means of the rivet 7.", secured to the link i, isjournaled to the latter the rotary or oscillating locking-disk 7v,having a cut-away portion at 7;, to permit the lip "on the head 1 to passbeyond said locking-disk 7:, when the cutaway portion 7a thereon is swung below such lip, after which the disk is is turned around its axis half a revolution, or more or less, to either side, causing a portion of the disk 7. to pass below the lip g, so as to lock the link i to the head as shown in the drawings; but it is very essential that while the block is in use the link. i should not get accidentally disconnected from the head 1 and for this purpose I provide said disk I; with a frictional retaining device, consisting of a tube or cup, 7.:, east on the outside of disk 7:, in which I lay a rubber or other yieldings pring, 7.", preferably between a pair of washers, 7; If, although this is not essential, and insert the rivet 7: from the outside through the rubber or other yielding spring 7; and its washers 7.1 7.2, and pass the lower end of such rivet through a small perforation in the bottom of cup 75, and rivet it to the link I. as shown in Fig. 2, the head of the rivet 7; pressing on top of yielding spring 7;", or on top of the uppermost washer 7.2", and in this manner I obtain a frictional retaining device for preventing the disk 7.: from turning around its axis, except when the operator manipulates it by taking hold of the lugs or ears 7; 7; on its outside, or turns it by other means.

To open the block for the purpose of inserting the rope, it is only necessary to turn the disk 7.1 around its fulcrum-pin 7; until the cutaway portion 7; comes opposite to the locking-lip f 011 the head y, when the link '1 may be swung upward around the hinge-pin i sufiiciently to enable the rope to be inserted, after which the link 1' is swung down to its nor mal position and the disk 7. turned around its center to look under the lip g", as shown in Figs. 1 and 2.

The invention may be modified as follows: Instead of hinging the link i to the side piece, (1 and looking it to the end of head g, I may reverse this arrangement by hinging the said link to the end of head 1 and to look its 0th or end to the side piece, a, or to the metal strap a. The disk In may also to equal advantage be located above or on one side of the projection y, instead of below it, as shown in the drawings.

I also desire to state that I do not wish to confine myself to the exact frictional retain ing device on the button or disk 7-, as this may be varied without departing from the spirit of the invention. The main thing is to provide such button with a frictional retaining device for the purpose, as set forth.

This improved snatch-block may be opened and closed without raising or moving it, thus saving much valuable time in its operation. It cannot get accidentally open when in use, and it is very strong, durable, and simple in its construction, as well as very neat in style and finish.

hat I wish to secure by Letters Patent and claim is- 1. In a snatch block, the heady, hinged to the bow-strap b on the side piece I), and for the purpose set forth.

2. In a snatch-block, the side pieces, a b, having the bow-straps a b, as described, and the head r hinged to bow-strap b, and link 1', hinged to the bow-strap a, as and for the purpose sct forth.

3. In a snatch-block, the side pieces, a b, and their respective bow-straps e b, in combination with the head 5 hinged to bow-strap b, and havinglocking projection 1/, with lip 9 adapted to be locked to the link i, hinged to bow-strap a, or its equivalent, and having locking-disk 7:, as and for the purpose set forth.

4-. In a pulley-block, the sides a Z), in combination with the end piece, f, and its metal shield or casingf, as and for the purpose set forth.

5. In a snatch-block, the sides (Lb, with their two bow-straps a I), as and for the purpose set forth.

6. In a snatch-block, the hinged link i and its locking button or disk 7.7, combined with the frictional or equivalent retaining device, substantially as and for the purpose set forth.

In testimony whereof I have affixed my nature in presence of two witnesses.

THOMAS R. FER ALL \Vitnesscs:

Ann): Axnin'aiv, l lm'nv UIIADIEOURX. 

